If you have been reading about Bremelanotide and want a single page that covers the useful parts, this is it: definitions, context, how it is studied, and the questions that come up repeatedly.
Last reviewed on 2025-09-15. Where a claim depends on a specific study, the study is described rather than over-claimed.
Bremelanotide acts as a non-selective agonist at melanocortin receptors, with reported activity at MC1R, MC3R, MC4R and MC5R. The proposed basis for its central effects is activation of MC4R populations in the hypothalamus, a region associated with appetite and reproductive signalling. Because the peptide carries a net positive charge and polar side chains, it does not cross biological membranes freely, which is one reason oral administration is not the standard route. Effects generally appear within an hour of parenteral administration and are described as centrally mediated rather than peripheral.
Bremelanotide, developed under the code PT-141, is a synthetic cyclic heptapeptide analogue of alpha-melanocyte-stimulating hormone. Its structure is Ac-Nle-cyclo[Asp-His-D-Phe-Arg-Trp-Lys]-OH, with a lactam bridge joining the aspartate and lysine side chains. The molecule has the formula C50H68N14O10 and a monoisotopic mass near 1025 daltons. It is commonly prepared as the acetate salt and appears as a white to off-white lyophilised powder in solid form. The free acid is the pharmacologically relevant species, while the counter-ion improves handling and dissolution.
Early research on PT-141 grew out of work on melanotan II, a related cyclic peptide studied for pigmentation. Investigators observed that centrally acting melanocortin agonists also influenced sexual behaviour in animal models, and the programme shifted toward that endpoint. A nasal formulation was evaluated in clinical trials but showed inconsistent absorption, and later studies used subcutaneous administration instead. Regulatory approval in the United States followed in 2019 for a defined population of premenopausal women with acquired, generalised hypoactive sexual desire disorder. That approval was specific to that group rather than a broad indication.
Clinical development of bremelanotide proceeded through several reformulation attempts. An early intranasal version was discontinued, and a subcutaneous auto-injector formulation later received approval for hypoactive sexual desire disorder in premenopausal women. Approval decisions have varied by country and over time, and the product has not been universally adopted. Blood pressure elevation is a documented effect, which is why some jurisdictions require monitoring after administration. The clinical evidence base continues to evolve as additional studies are published.
Bremelanotide is a cyclic heptapeptide that acts as an agonist at melanocortin receptors. It binds MC1R, MC3R, MC4R, and MC5R, with MC4R activation considered most relevant to sexual desire pathways in the central nervous system. The molecule is a synthetic analog of alpha-melanocyte-stimulating hormone, a naturally occurring peptide involved in pigmentation and energy regulation. Early research explored its use in tanning before attention shifted toward sexual dysfunction applications. Receptor binding affinity varies across these subtypes.
| Property | Value | Notes |
|---|---|---|
| Chemical class | Cyclic heptapeptide | Synthetic analogue of alpha-MSH |
| Molecular formula | C50H68N14O10 | Acetate salt form commonly reported |
| Molecular mass | ~1025 Da | Monoisotopic value near 1025.2 |
| Key structural motif | Lactam bridge | Asp side chain to Lys side chain |
| Solid appearance | White to off-white powder | Lyophilised and hygroscopic |
Clinical development proceeded through two routes of administration. An intranasal formulation advanced first, but variable absorption and tolerability problems led to a switch to subcutaneous injection. The United States Food and Drug Administration approved the subcutaneous product in 2019 for hypoactive sexual desire disorder in premenopausal women. Marketing rights subsequently changed hands, and commercial availability has fluctuated since approval. Use in men, in postmenopausal women, and in combination with other agents remains outside the approved label.
Outside the approved product, bremelanotide circulates as a research chemical sold by peptide vendors, often labelled PT-141. Such material is not manufactured under pharmaceutical quality standards, and independent testing has repeatedly found content that differs from the label. Analytical certificates supplied with a purchase are not strong evidence of purity because they are usually generated by the seller. Online discussion tends to blur the distinction between the approved drug and unregulated powder, which complicates interpretation of reported experiences.
PT-141 is the original development code for bremelanotide, a synthetic peptide first studied as a potential tanning and sexual-response agent in the 1990s. Researchers at a small American biotechnology firm designed it as a shortened analogue of melanotan II, which itself came from work on alpha-melanocyte-stimulating hormone. Early screening focused on pigmentation, but behavioural observations in animal models redirected attention toward sexual motivation. That shift made PT-141 one of the first melanocortin compounds investigated specifically for effects on desire rather than on skin colour.
Development of the peptide passed through several delivery formats, including an intranasal version tested in early trials and an injectable version that entered later clinical study. Regulatory approval for a subcutaneous product in the United States was granted in 2019 after review of controlled trials in premenopausal women. Outside the clinic, the compound circulates in research and non-pharmaceutical markets under its code name, where identity and purity vary considerably between suppliers. Synonyms appearing across technical literature include bremelanotide, PT-141, and Palatin 141.
PT-141 is the research designation for bremelanotide, a synthetic cyclic heptapeptide developed as a melanocortin receptor agonist. The peptide contains seven amino acids with an internal lactam bridge that constrains the backbone into a stable ring. Cyclisation of this kind improves resistance to enzymatic degradation relative to linear analogues. The compound was first explored for effects on melanin production, because several melanocortin receptors influence pigmentation. Its later association with sexual desire emerged from observations made during that early work, and the molecule became the subject of a separate development programme.
Levodopa, also known as L-DOPA, is a dopaminergic medication which is used in the treatment of Parkinson's disease (PD) and certain other conditions like dopamine-responsive dystonia and restless legs syndrome. The drug is usually used and formulated in combination with a peripherally selective aromatic L-amino acid decarboxylase (AAAD) inhibitor like carbidopa or benserazide. Levodopa is taken by mouth, by inhalation, through an intestinal tube, or by administration into fat (as foslevodopa).
=== The New York Times === On April 2, 2023, the main account for The New York Times became one of the first major media companies to lose its verified status on Twitter. Ahead of the official release of Verification for Organizations, newspaper The New York Times stated that it would not pay for a verification checkmark. In response to a Twitter user who pointed out the newspaper's decision, Musk stated, "Oh ok, we'll take it off then". Musk then called The New York Times hypocritical for charging readers to read its articles. He criticised the newspaper for tweeting hundreds of posts every day, including drafts that were not accepted into the published editions of the paper, and inundating the daily feed of users who followed it. Despite the deadline for Twitter Blue passing, and aside from The New York Times, many legacy verified accounts continued to retain their verified status. According to The New York Times themselves, the top 10,000 Twitter accounts and top 500 advertisers would be exempt from paying.
== Other definitions == In biological wastewater treatment processes, such as the activated sludge process, the term "biomass" is used to denote the mass of bacteria and other microorganisms that break down pollutants in wastewater. The biomass forms part of sewage sludge. Waste biomass fibre - potential source for cleaner production of textiles. Biomass (satellite) - an Earth observation satellite.
On Czapek Yeast Extract Agar medium at 25 °C, white colonies grow in a plane, attaining a velvety to deeply floccose texture, with colony sizes that are 33–35 mm in diameter. On this medium, olive conidia are produced. The reverse of the plate can be pale or slightly tinted brown. On Malt Extract Agar medium at 25 °C, growth is rare, yet rapid when occurring, forming a velvety surface. At first, colonies are yellow-green, but ultimately turn olive due to conidial production. Colony diameter can range in size from 35 mm to 70 mm. The reverse of the plate is similar to that observed for Czapek Yeast Extract Agar medium. On 25% Glycerol Nitrate Agar at 25 °C, colony growth is planar, yet develops into a thick gel, with colony size diameter ranging from 6–12 mm. The back of the plate is described as pale or olive. At 5 °C, 25% Glycerol Nitrate Agar supports germination and a colonial growth of up to 3 mm in diameter. This species fails to grow at 37 °C. On Creatine Sucrose Agar at 25 °C, colony size diameter ranges from 4 to 10 mm. Growth is restricted, and medium pH remains around 7. No change on the back of the plate is noted. Growth on media containing orange fruit pieces for seven days at room temperature results in fruit decay, accompanied by a characteristic odour. After 14 days at room temperature, the reverse is colourless to light brown.
The Parliament of Jamaica is the legislative branch of the government of Jamaica. It is a bicameral body, composed of an appointed Senate and an elected House of Representatives. The Senate (upper house), the direct successor of a pre-Independence body known as the "Legislative Council"—comprises 21 senators appointed by the governor-general: thirteen on the advice of the prime minister and eight on the advice of the leader of the opposition. The House of Representatives, the lower house, is made up of 63 (previously 60) members of Parliament, elected to five-year terms on a first-past-the-post basis in single-seat constituencies.
Sources: en.wikipedia.org
"Dude, people just don't want to eat pink slime". MarketWatch. Retrieved April 4, 2012. Greene, Joel L. (April 6, 2012). "Lean Finely Textured Beef: The 'Pink Slime' Controversy". Congressional Research Service. Retrieved March 2016. Gruley, Bryan; Campbell, Elizabeth (April 12, 2012). "'Pink Slime' Furor Means Disaster For U.S. Meat Innovator". Bloomberg. Retrieved July 19, 2012. Glen, Barb (June 22, 2012). "Lessons learned for Cargill in pink slime's 'ick' factor". The Western Producer. Retrieved July 18, 2012. "Pink slime saga boosts beef exports". The Australian. June 19, 2012. Retrieved July 18, 2012. Wessler, Brett (June 25, 2012). "Former BPI employee plans lawsuit for pink slime frenzy". Drovers/CattleNetwork Magazine. Archived from the original on May 1, 2013. Retrieved July 18, 2012. Siefer, Ted (July 10, 2012). "School board votes to donate 'pink slime'". New Hampshire Union Leader. Archived from the original on June 17, 2013. Retrieved July 18, 2012. Stebbins, Christine (July 12, 2012). "Cargill buys AFA Foods Fort Worth beef processing plant". Reuters. Retrieved October 10, 2013. Engber, Daniel (October 25, 2012). "The Sliming". Slate. Retrieved March 25, 2016. Russell, Joyce (June 19, 2014). "'Pink Slime' Is Making A Comeback. Do You Have A Beef With That?". NPR. Retrieved March 24, 2016. Isidore, Chris (August 13, 2014). "'Pink slime' is back and headed for your burger". CNN Money. Archived from the original on August 16, 2014. Retrieved March 25, 2016. Sanburn, Josh (August 26, 2014). "'Pink Slime' Ground Meat is Back". Time. Retrieved March 24, 2016.
Diphenhydramine, or Diphenylhydramine, sold under the brand name Benadryl among others, is an antihistamine and sedative. Although generally considered sedating, diphenhydramine can cause paradoxical central nervous system stimulation in some individuals, particularly at higher doses. This may manifest as agitation, anxiety, or restlessness rather than sedation. It is a first-generation H1-antihistamine (i.e. it blocks histamine) with sedative effects. Diphenhydramine is also a potent anticholinergic. It is mainly used to treat allergies, insomnia, and symptoms of the common cold. It is also less commonly used for tremors in parkinsonism, and nausea. It is taken by mouth, injected into a vein, injected into a muscle, or applied to the skin. Maximal effect is typically around two hours after an oral dose, and effects can last for up to seven hours. Common side effects include sleepiness, poor coordination, and an upset stomach. There is no clear risk of harm when used during pregnancy; however, use during breastfeeding is not recommended. It was developed by George Rieveschl and put into commercial use in 1946. It is available as a generic medication. In 2023, it was the 294th most commonly prescribed medication in the United States, with more than 700,000 prescriptions. Its sedative and deliriant effects have led to some cases of recreational use.
=== Sources === Freedberg IM, Eisen AZ, Wolff K, Austen KF, Goldsmith LA, Katz SI, eds. (2003). Fitzpatrick's Dermatology in General Medicine (6th ed.). McGraw-Hill. ISBN 978-0-07-138076-8. James W, Berger T, Elston D (2005). Andrews' Diseases of the Skin: Clinical Dermatology (10th ed.). Saunders. ISBN 978-0-7216-2921-6. Rapini RP, Bolognia JL, Jorizzo JL (2007). Dermatology: 2-Volume Set. St. Louis: Mosby. ISBN 978-1-4160-2999-1.
In collaboration with Professor Jack Henion at Cornell University and Dr. Peter Dawson at the National Research Council of Canada, the first application of liquid chromatography-mass spectrometry-mass spectrometry (LC-MS-MS) was demonstrated on the TAGA 6000 in 1982. This proof of concept led to the development of the heated nebulizer LC interface for APCI, using pneumatic nebulization to allow the full LC flow to enter the ion source. In 1983, LC-MS-MS using ion evaporation, a spray method similar to electrospray but compatible with higher flow rates of up to 1 mL/min, was demonstrated on the TAGA 6000 but was not commercialized. The API III LC-MS-MS system introduced in 1989 provided both ion spray (developed by Bruins, Covey and Henion at Cornell University) and heated nebulizer LC inlets on a triple quadrupole platform based on the TAGA 6000 architecture. It was the second commercial LC-MS in the market, and the first that provided electrospray ionization. The atmospheric pressure spray methods of electrospray, ion spray and APCI which helped to drive the burgeoning LC-MS market are now available on a wide variety of MS platforms and from a variety of vendors. In 1998, the cryopump API III platform began to be replaced with turbo-molecular-pumped single and triple quadrupole mass spectrometer products that evolved from the API 2000 (benchtop) and API 3000 to the current API 7500 series.
Sources: en.wikipedia.org
PT-141 was the development code used for bremelanotide during its preclinical and early clinical programme. The peptide is now generally referred to by its international nonproprietary name.
The two compounds share the same cyclic core and are both non-selective melanocortin agonists. They differ chiefly at the C-terminus, where bremelanotide carries a free carboxylic acid and melanotan II a terminal amide.
Receptor binding profiles are well characterised in vitro, but the downstream pathway linking MC4R activation to behavioural effects is not fully mapped. Several intermediate neural circuits have been proposed without definitive confirmation.
PT-141 is the research code for bremelanotide, a cyclic peptide developed as a melanocortin receptor agonist. The code has appeared in literature and catalog listings since early development. Bremelanotide is the international nonproprietary name.